Recently, the Ministry of Water Resources released the 2022 China River Sediment Bulletin. The communiqué shows that in 2022, the total annual sand transport volume of representative hydrological stations of China's major rivers has shown a small trend in the past 10 years.
According to the 2022 China River Sediment Bulletin recently released by the Ministry of Water Resources. In 2022, the total measured runoff of representative hydrological stations of major rivers in China will be 13320,7 billion cubic meters, which is 3% smaller than the average annual runoff for many years. The total annual sand transport volume of the main rivers representing hydrological stations is 90 million tons, which is 73% smaller than the annual average annual sand transport.
In recent years, China has vigorously carried out measures such as integrated protection and systematic treatment of landscapes, forests, fields, lakes, grass and sand, and compared with before 2000, the amount of sediment in the country's major rivers has been reduced by more than two-thirds.
Wang Yangui, senior engineer of China Institute of Water Resources and Hydropower Research: Looking at the spatial distribution of water and sand from different rivers, the average annual average sand transport of the Yellow River and Yangtze River representative stations accounts for 64% and 24% of the total respectively, while other rivers account for a relatively small proportion.
The amount of sediment in major rivers has decreased by more than 20/2 compared with more than 3 years ago
The communiqué released this time shows that compared with before 2000, the amount of sediment in the country's major rivers has been reduced by more than two-thirds overall.
The sediment status of rivers is not only related to the development and evolution of the river itself, but also reflects the environmental characteristics of the river basin, the degree of soil erosion and the impact of human activities. River sediment is an important factor that must be considered in planning, flood control, water resource utilization and protection, and soil and water conservation.
Guo Qingchao, director of the Sediment Research Institute of the China Institute of Water Resources and Hydropower Research: For example, more than 20 years ago, China's major rivers were dominated by siltation, especially in the lower reaches of the Yellow River, and the annual siltation raised the riverbed by about 5 to 10 centimeters, which brought great pressure to the flood control of the Yellow River.
In recent years, China has vigorously carried out measures such as integrated protection and systematic treatment of landscapes, waters, forests, fields, lakes, grass and sand, and up to now, the sediment content of major rivers has undergone great changes.
Guo Qingchao, director of the Sediment Research Institute of the China Institute of Water Resources and Hydropower Research: One is the sediment reduction effect of soil and water conservation in river basins. The second is in the river, because a lot of reservoirs have been built, and these sediments are blocked in the reservoir, which is very good for reducing siltation in the downstream river.
Experts said that like China's Yellow River, when flowing through the Loess Plateau, it carries a large amount of washed sediment and discharge, becoming the river with the highest sediment content in the world. In the 20s of the 90th century, China built a Xiaolangdi water conservancy hub in the middle reaches of the Yellow River, and through 22 years of water and sand transfer, the downstream flow capacity of the Yellow River has been significantly improved, and the flood level of the same flow has dropped by about 3 meters, effectively reducing the flood control pressure in the lower reaches of the Yellow River. (CCTV News Client)